foo(char *p, char n)
{
    long num;
    char *cp1, *cp2;
    num = -num;
    num = -n;
    *cp1 = -(*cp2);
    *cp1 = -(*cp1);

    num = !n;
    n = !num;
    *p = !num;

    return !(*(char*)1000);
}